parent_id,child_id,head_edge_id,inc_edge_id,out_edge_id
i0,u00,-571500487_01,571500487_02,571500487_01.32
i2,u20,571542811_02,571542810_01.51,571542810_02
i3,u30,571556450_02,571556452_01,571556452_02
i3,u31,-571500475_01,571500475_02,571500475_01.26
i3,u32,571540303_02.21,571540303_02,-571540303_02
i6,u60,571500535_02.18,571500535_02,-571500535_02